A much bigger block with a cavity/hole going through the center.
4" clean large stone
3/8" Chips. Very small stones
Regular 4" block with a 90 degree offset.
2" clean medium sized stone
Concrete block that weighs one tonne.
An empty small bag.
An empty big bag.
The bigger thicker blocks up from the 4"
Regular 4" block with a 30 degree offset.
Plastering sand